1.1 This engine oil test method covers the evaluation of automotive engine oils (SAE grades 5W 10W, 20, 30, 40, and 50, and multiviscosity grades) intended for use in either spark-ignition gasoline engines, or in diesel engines. The test procedure is conducted using a carbureted, spark-ignition Cooperative Lubrication Research (CLR) Oil Test Engine (referred to as the L-38 engine in this test method). An oil is evaluated for protection against engine and oil deterioration under high-temperature, heavy-duty service conditions. The test method can also be used to evaluate the viscosity stability of multiviscosity-graded oils.

1.2 The two measures of engine deterioration used in this test method are (1) weight loss of copper-lead bearings used in the test power section, and (2) varnish and sludge deposits on power section parts.

1.3 The two measures of oil deterioration used in this test method are (1) the change in the acid number of the oil, and (2) the change in the viscosity of the oil during the test period.

1.4 Correlation of test results with those obtained in automotive service has not been established. Furthermore, the results obtained in this test method are not necessarily indicative of results that will be obtained in a full-scale automotive spark-ignition or compression-ignition engine, or in an engine operated under conditions different from those of the test method. The test can be used to compare one oil with another.

1.5 The values stated in inch-pound units are to be regarded as the standard; except for the case of bearing weight measurements, for which the unit is milligram; and except for viscosity measurements, for which the temperatures of measurement are expressed in C (degrees Celsius). SI values are given in parentheses. In cases where materials, products, or equipment are available only in inch-pound units, SI units are omitted.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.